Definition
Brain death, also known as cerebral death, is the irreversible cessation of all brain functions, including the brain stem. It means the brain has completely and permanently stopped working. Think of it as the computer's hard drive being completely wiped with no hope of recovery. It's not just a coma; it's a definitive and final diagnosis. A person declared brain dead has no consciousness, cannot breathe on their own, and lacks reflexes. Brain death is the legal definition of death in many countries.